Efter strømafbrydelsen tjekker jeg sikringen og sikringsskabet.

Because Danish main clauses usually follow the V2 rule: the finite verb must be in the second position.

Here, Efter strømafbrydelsen comes first as a time phrase, so the verb tjekker has to come next:

• Efter strømafbrydelsen = first element
• tjekker = second element
• jeg = subject

So the structure is natural Danish word order.

The ending -en marks the noun as definite singular — in other words, the power outage.

• en strømafbrydelse = a power outage
• strømafbrydelsen = the power outage

Danish often adds the definite article directly to the end of the noun instead of using a separate word like the.

For the same reason: Danish uses a suffixed definite article.

• en sikring = a fuse / a breaker

• sikringen = the fuse / the breaker

• et sikringsskab = a fuse box / electrical cabinet
• sikringsskabet = the fuse box / the electrical cabinet

In this sentence, the speaker is talking about the specific fuse and fuse box relevant to the situation, so the definite forms sound natural.

Sikringen is the actual fuse or circuit breaker.

Sikringsskabet is the box/cabinet that contains the fuses or breakers — in English, often the fuse box or electrical panel.

So:

• sikringen = one protective device
• sikringsskabet = the place where those devices are housed

Because Danish, like German, makes heavy use of compound nouns, and they are usually written as one word.

So:

• sikring = fuse / protection device
• skab = cabinet / box
• sikringsskab = fuse cabinet / fuse box

Then the definite ending is added:

• sikringsskabet = the fuse box

This is completely normal in Danish.

That -s- is a linking element often used in Danish compounds.

So the word is built like this:

• sikring
• • s
• • skab
• = sikringsskab

The -s- does not usually have a separate meaning by itself. It simply helps connect the parts of the compound in a natural way.

Tjekker is present tense.

The infinitive is at tjekke = to check.

So:

• jeg tjekker = I check / I am checking

As in English, the exact meaning depends on context. In this sentence, it describes what the speaker does after the outage.

Yes. Efter is a preposition meaning after, and it can be followed directly by a noun phrase.

So:

• efter strømafbrydelsen = after the power outage

That part of the sentence is completely normal.

No. Another very common word is strømudfald.

So you may also hear:

• Efter strømudfaldet tjekker jeg sikringen og sikringsskabet.

Both are correct. Strømafbrydelse may sound a little more formal or technical in some contexts, while strømudfald is very common in everyday speech.

No, not normally.

A short fronted time phrase like Efter strømafbrydelsen does not need a comma before the rest of the sentence. So the sentence is correctly written without one.